THIS invention relates to a method of manufacturing single crystal diamond substrates for use in device applications, and to diamond wafers for use in such a method.
Diamond offers a range of unique properties, including optical transmission, thermal conductivity, stiffness, wear resistance and electronic properties. Whilst many of the mechanical properties of diamond can be realised in more than one type of diamond, other properties are very sensitive to the type of diamond used. For example, for the best electronic and other properties, CVD single crystal diamond is important, often outperforming polycrystalline CVD diamond, HPHT diamond and natural diamond.
There are many applications where the workable area or surface of the final diamond product is very small. In such applications it is often difficult to achieve economies of scale or to provide practical methods of processing the single crystal diamond substrates into the desired devices. Thus, for example, the manufacture of electronic devices on the surfaces of small individual diamond substrates is problematic. Conventional lithographic techniques and existing lithography equipment are not suited to realising some of the complex electronic structures envisaged for such single crystal diamond substrates.